Jonah Shacknai, the CEO of Medics Pharmaceutical Corporation, was planning to propose to his girlfriend, Rebecca Zahau, who was found dead at his Coronado, Calif. mansion, just days after his son Max, suffered a fatal fall at the historical estate, RadarOnline.com is exclusively reporting.

Jonah’s son, six-year-old Max, had fallen down the stairs just two days earlier and according to sources, was being watched at the time by Rebecca. Max subsequently died in hospital.

Shacknai had been dating the Burmese beauty for two years. “It was a very serious relationship. There was a lot of love there. Jonah had every intention of proposing to Rebecca. Jonah wanted to spend the rest of his life with her,” a source close to the former couple tells RadarOnline.com.

San Diego Sheriff’s Department has ruled Rebecca’s death as “very suspicious.”

Jonah wasn’t home at the time his girlfriend’s body was discovered, he was at his son Max’s bedside, keeping vigil. Law enforcement is also investigating Max’s death, but: “At this time, we have no information that would lead us to believe this is anything other than a tragic accident with the child,” Coronado Police Chief Louis Scanlon said last Thursday.

As RadarOnline.com previously reported, Jonah, and his ex-wife, Dina Shacknai, made the brave decision to donate their son’s organs, which ultimately saved three different children’s lives.

“Jonah and Dina didn’t want another family to go through the horrible loss they are dealing with, so they decided to donate Max’s organs. They are absolutely devastated by Max’s death. There simply are no words,” the family insider told RadarOnline.com.